The Villa boss picked up his first league win in charge at Villa Park, having seen Saido Berahino cancel out Gabriel Agbonlahor's opener in the Midlands derby.
However, Christian Benteke ensured the three points with a 94th-minute penalty after Ben Foster brought down Matthew Lowton, ending Villa's run of seven top-flight defeats to lift them out of the bottom three.
Asked whether it could be a turning point in Villa's season, Sherwood said: "Yeah, I think so. It was huge.
"Even though we deserved to win the game, you still need a slice of luck in that last minute or so to turn the points our way.
"We've improved every game and I think [this] was the best performance, especially in the first half.
"We dictated the pace of the game, controlled the football, moved it through midfield, created chances and should have been more than 1-0 up.
"We got undone but we stuck at it. But I didn't expect [the chance] to be that late and it's a magnificent feeling.
"It was a sickener when we lost in the 93rd minute at Stoke and it certainly feels better to be on the other side."
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